Abstract

This paper presents experimental measurements of the
performance of a new film cooling hole geometry - the
Converging Slot-Hole or Console. This novel, patented
geometry has been designed to improve the heat transfer and
aerodynamic loss performance of turbine vane and rotor blade
cooling systems. The physical principles embodied in the new
hole design are described, and a typical example of the console geometry is presented.
The cooling performance of a single row of consoles was
compared experimentally with that of typical 35° cylindrical
and fan-shaped holes and a slot, on a large-scale, flat-plate model at engine representative Reynolds numbers in a low speed tunnel with ambient temperature main flow. The hole throat area per unit width is matched for all four hole geometries. By independently varying the temperature of the heated coolant and the heat flux from an electrically heated, thermally insulated, constant heat flux surface, both the heat transfer coefficient and the adiabatic cooling effectiveness were deduced from digital photographs of the colour play of narrowband thermochromic liquid crystals on the model surface.
A comparative measurement of the aerodynamic losses
associated with each of the four film-cooling geometries was
made by traversing the boundary layer at the downstream end of the flat plate.
The promising heat transfer and aerodynamic performance
of the console geometry have justified further experiments on an engine representative nozzle guide vane in a transonic
annular cascade presented in Part 2 of this paper [1].